Re: 10v turbo exhaust manifold

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <000301bee836$186060c0$553661cb@george> "Rex Archer" writes:

> Dear Mr.Payne,
>                            My 200qt avant has a cracked exhaust manifold and
> I have been contemplating purchasing a Dialynx replacement.However
> after reading your obvious dislike of these manifolds in the quattro list,
> I have had second thoughts.
> What is it you dont like about these manifolds?I have heard they are
> difficult to fit,but have also heard that they flow better than the standard
> one.The Audi three piece replacement is very expensive,but is it an
> improvement over the old one piece performance wise?
> Your opinion on this would be helpful.

a) They warp like wet boards, pulling studs out of the head.  They're
   tolerable for collectors with 2144cc mechanical lifter cars that
   aren't driven more than 2,000 miles a year, but every one I've heard
   of fitted to a 2226cc hydraulic lifter car (MC, MB, 1B engines) has
   failed.

b) If they flow better than stock Audi, I would be surprised.  The
   casting is _much_ simpler - the Audi stock design divides the airflow
   into three channels to the turbo, combining two pairs of cylinders
   into two channels to create a sustained scavenging gasflow.  The lip
   to the port is also the same size as the port - in the Audi manifold
   it's slightly larger, again to promote scavenging.

c) They're bastards to fit.  The exhaust nut seats have to be machined
   flat because Dialynx never does it adequately.  Three of the nuts
   can't be reached from vertically above, so a special thin-walled
   six-point ring (box) spanner has to be used instead of a torque
   wrench.  The raised "Dialynx" lettering interferes with the Allen
   driver used to fix the inlet manifold.

d) Here in the UK, they're no cheaper than stock Audi.  Check the
   dealership price, then show them a Dialynx advert and ask again.
   Audi dealers here will match Dialynx's price.

The Audi replacement is actually 7-piece, I think.  Make sure they ship
you a blanking bolt for the measurement hole - they don't do this by
default.  You can get a replacement one-piece from Audi by ordering for
the MB (ur-quattro) engine.

--
 Phil Payne
 UK Audi quattro Owners Club
 Phone: 0385 302803   Fax: 0870 0883933